Target vibration isolation mount



July 5, 1966 J, NEY

TARGET VIBRATION ISOLATION MOUNT Filed June 12, 1964 FIG.|

INVENTOR: ROBERT J. NEY,

HIS ATTORNEY.

United States Patent 3,259,774 TARGET VIBRATION ISOLATION MOUNT Robert J. Ney, Liverpool, N.Y., assignor to General Electric Company, a corporation of New York Filed June 12, 1964, Ser. No. 374,672 9 Claims. 81. 313-67) This invention relates to an improved vibration isolation mounting assembly and more particularly to an improved target vibration isolation mounting assembly as utilized in image orthicon electron image tubes.

In the operation of an image orthicon type camera tube, light falling on a photo-sensitive surface of the tube produces an emission of electrons which are accelerated axially toward, and impinge upon, a transversely extending charge storage target. The primary electrons arriving at the charge storage target produce emission of secondary electrons whch are collected by a closely spaced confronting foraminate or mesh-like electron collector electrode leaving a charge pattern on the storage target which is image representative of the optical image supplied to the photo-sensitive surface of the tube. The storage information is read out as modulation of the returned current of an electron beam which scans the storage target.

In image orthicon camera tubes of the type described, even slight and otherwise limited relative motion between the charge storage target and the adjacent electron collector mesh electrode has severe and adverse effects on the quality of a picture or image reproducible from the signal read out from the tube. Such relative motion is usually indicated in the reproduced picture as microphonic bar patterns, which, of course, severely impair the fidelity of the resulting picture. Furthermore, the usual close spaced planar target and planar mesh electrode are frequently supported in drumhead fashion exclusively from an annular or peripheral frame and are therefore quite susceptible to relative movement in an axial direction towardand away from one another when the camera tube is subjected to vibration at frequencies which approach any of those resonant frequencies associated with a target or collector electrode.

Accordingly, it is an object of the present invention to provide an improved vibration isolation mounting means.

It is another object of this invention to provide improved Vibration isolation mounting means which employ a plurality of vibration damping intertwined fiber members peripherally positioned about a predetermined periphery between a moving and a fixed system.

It is a further object of this invention to provide an improved vibration damping isolation mounting assembly employing a plurality of vibration damping intertwined fibrous members equidistantly peripherally positioned between a stationary and a moving system on two different sides of the moving system.

It is a still further object of this invention to provide a vibration damping isolation mounting assembly which employs a plurality of vibration damping interwoven fibrous members, equally peripherally positioned between a stationary and a moving system on opposite sides of the moving system and constituting a tension support for the moving system.

It is yet another object of this invention to provide an improved vibration isolation system for a target assembly in image orthicon camera tubes Where equidistant peripherally positioned metallic fiber members are angularly attached to opposite sides of the target assembly for tension support thereof.

Briefly described, this invention in one of its preferred forms includes an annular support member having a ra-- dially inwardly directed flange. An annular target supice port structure having a radially outwardly directed flange is concentrically positioned within the annular support member so that the flanges are in spaced axial relationship. A plurality of fibrous vibration damping material members are equally peripherally positioned between the said flanges, and attached to each, to support the target. A plurality of tabs are positioned on the target support structure to be adjacent an opposite side of the flange of the annular support, so that the annular support flange is between the tabs and the target flange. These tabs are equally peripherally positioned about said target to be peripherally intermediate the mentioned damping material members. A further plurality of fibrous vibration damping material members are positioned one between each tab and adjacent flange and are attached to each.

This invention will be better understood when taken in connection with the following description and the drawings in which FIGURE 1 is an axial sectional view of the image portion of an image orthicon type of camera tube,

FIGURE 2 is a transverse partially sectioned end view of the structure of FIGURE 1 taken on the line 22.

Referring now to FIGURE 1, there is illustrated a portion of the image end section of a pickup camera tube 10 of the image orthicon type. Reference is made to U.S. Patents 3,038,094, Ney, and 3,090,881, Wellinger, each assigned to the same assignee as the present invention, for further descriptive material of these pickup camera tubes and functional relationships of their elements. Tube 10 includes an evacuated envelope 11, having at its forward end a viewing window 12. On the interior surface of the viewing window 12 is a photo-sensitive layer 13 which is responsive to the light image falling thereon. This responsiveness is indicated by electrons being emitted from the layer 13 and accelerated axially or longitudinally by an annular accelerating electrode 14 and an annular target cup electrode 15 to a transverse planar member like electric charge storage target 16. The primary electrons impinging the charge storage target 16 produce emission of secondary electrons which are then collected by a mesh-like electron collector electrode 17 disposed in closely spaced and confronting relationship with the forward face of the target 16. An electrical charge pattern is thus formed on the charge storage target 16 which is representative of the light image falling on the photo-emissive layer 13.

The cup electrode 15 is a peripheral and preferably annular support member having a radially inturned flange 18 at one end thereof. Depending on the particular needs and design of the tube 10, the electrode 15 and depending flange may be peripherally or axially coextensive surfaces or composed of a plurality of surfaces electrically cooperative to provide the desired results.

The target and collector electrode frame assembly 19 includes a peripheral and preferably annular member 20 having a radially outwardly directed flange 21 at one end thereof. Frame assembly 19 is adapted to contain or receive a combined target and collector electrode unit 22 which is schematically illustrated in dash lines in FIGURE 1. Unit 22 which is releasably secured concentrically within member 20, carries the storage target 16 and collector electrode 17. The frame supporting assembly 19 constitutes a moveable member or assembly while the cup electrode 15 constitutes a stationary or fixed member or assembly. The vibration damping means of this invention is applied between the mentioned moveable and fixed members. a

More particularly, the annular member 20 is concentrically positioned within cup electrode 15 so that flange 21 is in confronting and close spaced axial relationship to flange 18 of member 15. Flange 21 is also described Patented July 5, 1966 as being positioned on the forward face or end side of flange 18, i.e., on the viewing window side. At the rearward or opposite side of both the annular member 20 and flange 18, a plurality of L-shaped tab members 23 are attached to member 20 so that the tab members 23 and flange 21 define an intermediate space containing the radially inwardly directed flange 18. T ab members 23 may be extensions of an integral member or may also constitute a co-extensive annular member. A vibration damping material member 24 is interposed between a tab 23 and flange 18 to complete a vibration damping unit 25. Material 24 may be the essential supporting element to not only support the assembly 19 but also to provide vibration isolation therefor.

The vibration damping material 24 in one form of this invention comprises a material having high internal inherent friction damping characteristics. It is a particular feature of this invention that the vibration damping material 24 should have not only the desired mechanical properties for vibration and shock attenuation, but also to be compatible with the stringent requisites of a high vacuum image orthicon tube environment, in which the taget collector assembly is intended to operate. The particular feature to be taken into consideration for a choice of the vibration damping material 24 is the presence of the metal cesium or cesium vapor in image orthioon tubes. The adverse effects of this metal vapor on various materials in the tube is well known so that where this metal is so employed, the choice of vibration damping material is limited. Furthermore, the vibration damping material must be one of those materials having a sufliciently low vapor pressure or low capacity for occluded gases to avoid appreciable outgass'ing during tube operation. Suitable materials which will provide proper vibration damping in the practice of this invention are, for example, stainless steel, Monel metal, certain glasses, quartz, and other non-metallic materials. More particularly, in the practice of this invention, the vibration damping material preferably comprises a material of high internal friction damping characteristics such as bundles of fibres or strands of intertwined, interwoven, or resilient wool-like masses, pads, rolls, of metal. Preferred examples are suitably formed steel wool and metal braid. For example,'in one working embodiment of this invention, the mate-rial 24 was of .002 diameter Inconel 600 wire which was interwoven in knitted form and of a rectangular configuration of about 0.375 inch length and 0.25 inch width.

The material 24 may be suitably contained between flange 18 and a tab 23 so that relative motion therebetween is transmitted through the material 24. In one preferred form of this invention, material 24 in the form of the the interwoven metal strip as described is attached to cup member adjacent the forming curve of flange 18 by welding. The other end of the strip is attached to and partly between tab 23 and annular member 20. This arrangement provides an angular relationship between the plane of the strip 24 and the plane of flanges 18 and tabs 23 for increased vibration damping characteristics.

A tab 23, adjacent portion of flange 18, and the inter mediate vibration damping material 24 constitutes a vibration damping unit 25. The damping unit 25 is utilized in plural or extended form about the periphery of annular member or cup electrode 15. For example, in one preferred form of this invention, three such units are employed equally peripherally spaced about annular member 20. This arrangement is more clearly illustrated in FIGURE 2 where the three vibration damping units 25 are spaced 120 apart between cup electrode 15 and annular member 20. Each of the units 25 are at the rear face of flange 18.

A particular feature of this invention lies in the use of a further plurality of vibration damping units 25'. Units 25, as illustrated in FIGURE 2, are positioned equally peripherally spaced in the defined circle of units 25, and equally peripherally spaced so that one unit 25' resides intermediate a pair of adjacent units 25. The operative relationship of units 25 is different from that of units 25. For example, referring again to FIGURE 1, unit 25' includes a similar vibration damping material strip 24 which is positioned on the forward side of flange 13 and attached to an area of flange 13 adjacent the forming bend thereof. The other end of the strip 24' is attached to annular member 29 at the juncture thereto of flange 21. The prescribed arrangement} provides an angular relationship between the plane of the strip 24 and the flange 21 which is oppositely directed to that as described for strip 24 of unit 25. This arrangement increases the frictional damping characteristics of the overall assembly when annular member 20 is suspended by oppositely angularly directed vibration damping means. It is preferred that this angular relationship be maintained between about 5 to 10 to the vertical. The rubbing friction damping component of the assembly is increased when the inner surfaces of tab 23 and the adjacent surfaces of flanges 18 and 21 are at least in part contiguous to strips 24 and 24'.

In defining a pair of adjacent surfaces with an intermediate vibration damping material in accordance with the teachings of this invention, those flange and tab surfaces and their supporting structures may be coextensively annular as illustrated for members 18 and 21, for example, or may take separate or singular tab form. It is only necessary that a minimum of 3 positions he provided for each unit 25 or 25'. The three alternate vibration damping units may be applied to various other target support and electrode combinations of various configurations and broadly to charge storage target fixation per se. The particular embodiment illustrated and described is particularly adaptable to image orthicon tubes.

In some instances, it may be desirable to increase the resistance of the storage target frame 19 to purely lateral planar movement or to rotational movement. In these instances, a shear strip has been employed. Such a shear strip of about .002 inch thick metal foil may be suitably attached to both target support cup 19 and cup electrode 15 to limit maximum movement as described. One shear strip may be intermediately positioned between each vibration damping unit 24 or 25 so that three equidistance strips are employed.

A vibration isolating target mounting structure constructed as described is found to be extremely effective in preventing movement of the charge storage target relative to the collector electrodes at frequencies as have heretofore produced undesirable effects in the picture or other image produced from the output signal of the tube. Moreover, such a vibration damping mount permits extended damping movement of the target collector electrode assembly at low frequencies below the frequency of the resonance of the target or mesh electrode so as to preclude rupture or other injury to the target or mesh electrode when the tube is subjected to low frequency vibrations. It will be evident that such a mounting arrangement as herein described provides effective protection or ruggedization of the tube against the deleterious effects of vibration and enables continued operation of the tube with desirable picture quality under extremely adverse vibrational conditions.

It will be appreciated by those skilled in the art that this invention may be carried out in various ways in addition to that described, and may take various forms and embodiments other than those illustrated. Accordingly, it is to be understood that the scope of this invention is not limited to the details of the foregoing description but will be properly defined in the following claims.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In an image orthicon camera tube a vibration damping target support therefor comprising in combination (a) a first fixed electrode support having a depending surface,

(b) a moveable target containing frame having an upstanding surface,

(c) an intertwined metal fiber member attached to each said surface to support said moveable frame in tension, and

(d) at least three of said vibration damping supports being equidistantly peripherally positioned about said moveable frame for vibrational isolation thereof.

2. The invention as recited in claim 1 wherein at least six such supports are utilized with three on opposite sides of one of said supports.

3. A vibration damping system for an evacuated electron device comprising in combination (a) a supporting member constituting a fixed member,

(b) a moveable frame member attached to said supporting member,

(c) and vibration damping means interposed between said members,

(d) said vibration damping means including a rubbing friction vibration absorbing member attached to said moveable and said fixed members at each of 3 equally spaced peripheral positions on one side of one of said members,

(e) said vibration damping means including a rubbing friction vibration absorbing member attached to said moveable and said fixed members on an opposite side of said one of said members at 3 equally peripherally spaced positions 60 circumferentially removed from said other positions.

4. The invention as recited in claim 1 wherein said members constitute an intertwined fibrous material.

5. The invention as recited in claim 1 wherein said members constitute an intertwined metal fiber material angularly supporting said moving frame in tension.

6. In an image orthicon tube having a moveable frame member containing an electron storage target the combination comprising (a) a fixed support member for said moveable frame,

(b) said fixed support member having a forward and a rearward side,

(c) at least three vibration damping material means on the forward side of said support member and attached to said support member and said frame in angular relationship thereto to support said frame in tension,

(d) said three vibration damping means being attached to said target frame at three equidistant peripheral positions,

(e) at least three further vibration damping material means on the rearward side of said support member and attached to said support member and said frame in angular relationship thereto to support said frame in tension,

(f) said three further vibration damping material means being attached to said target frame at three equidistant peripheral positions peripherally removed from the said position on said forward side of said support,

(g) so that vibration of said target frame relative to said support is substantially damped by means of said material means.

7. The invention as recited in claim 2 wherein said material is a strip of intertwined metallic fibers.

8. In an image 'orthicon camera tube vibration isolation means for a target assembly comprising in combination (a) an annular control electrode support having a depending peripheral flange surface,

(b) an annular frame charge storage target support having a radially outwardly directed flange surface,

(c) said target support being positioned concentrically within said control electrode with said flanges in close spaced axial relationship,

(d) at least three strips of interwoven metal fiber attached between and to said flanges to support said target support in tension,

(e) said strips being equidistantly positioned about said supports at spacings,

(f) at least three L-shaped tabs peripherally positioned and attached to said target support at 120 spacings 60 removed from thespacings of said strips,

(g) said tabs having upstanding surfaces facing the side of said depending flange opposite to that faced by said target flange, and

(h) an additional said strip between and attached to each said upstanding tab surface and said depending flange surface to support said frame in tension so that axial vibration of said target support is effectively damped.

9. The invention in claim 8 wherein at least three metal foil shear strips are employed equidistantly peripherally between said strips and attached to said support and said frame.

References Cited by the Examiner UNITED STATES PATENTS 6/1962 Ney 3l367 6/1964 Ney et a1. 3l367 

1. IN AN IMAGE ORTHICON CAMERA TUBE A VIBRATION DAMPING TARGET SUPPORT THEREFOR COMPRISING IN COMBINATION (A) A FIRST FIXED ELECTRODE SUPPORT HAVING A DEPENDING SURFACE, (B) A MOVEABLE TARGET CONTAINING FRAME HAVING AN UPSTANDING SURFACE, (C) AN INTERTWINED METAL FIBER MEMBER ATTACHED TO EACH SAID SURFACE TO SUPPORT SAID MOVEABLE FRAME IN TENSION, AND (D) AT LEAST THREE OF SAID VIBRATION DAMPING SUPPORTS BEING EQUIDISTANTLY PERIPHERALLY POSITIONED ABOUT SAID MOVEABLE FRAME FOR VIBRATIONAL ISOLATION THEREOF. 